The goal of this project is to develop an optical probe for detecting calculus deposits on teeth. There is evidence that calculus engenders a distinguish able optical signal which can be read with fiber optic sensor instrumentation. The purposes of this Phase l study are to further investigate the spectral properties of calculus enabling its differentiation, and conduct clinical studies showing the feasibility of a fiber optic system to sense calculus in situ. A systematic study of the spectra of calcified dental plaque deposits will be performed. A fiber optic instrument will be built to the specifications optimal for deposit detection and characterized for specific detection capabilities. The system will be evaluated through prospective and retrospective testing with patients. The technology has considerable potential value in the practice of dentistry. It could increase the efficiency of examinations and efficacy of therapy. The reliable detection and removal of calculus is an essential part of achieving periodontal health.